Reversibly thermochromic compositions

ABSTRACT

A reversible thermochromic system comprising a) a compound of the formula (IA) or a tautomer thereof or a compound of the formula (IB) or a tautomer thereof (IA) (IB) wherein R 1  is C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 3 -C 12 cycloalkyl, C 3 -C 12 cycloalkyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; phenyl, phenyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; or C 7 -C 12 phenylalkyl; R 2  is hydrogen or a group —SO 2 —R; R 3  and R 4  independently of one another are hydrogen, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 3 -C 12 cycloalkyl, C 3 -C 12 cycloalkyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; phenyl, phenyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; or C 7 -C 12 phenylalkyl; and R is C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 3 -C 12 cycloalkyl, C 3 -C 12 cycloalkyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; phenyl, phenyl substituted by 1, 2 or 3 C 1 -C 4 alkyl; or C 7 -C 12 phenylalkyl; and b) a compound containing a group of the formula (III).

The present invention pertains to a reversible thermochromic systemcomprising a substituted or an unsubstituted 1,4-dihydroxy-anthraquinoneand a 2,2,6,6-tetramethylpiperidine derivative, and to a compositioncomprising the reversible thermochromic system and a carrier material aswell as to novel substituted or an unsubstituted1,4-dihydroxy-anthraquinones.

Known reversible organic thermochromic systems consist of a basic colorformer such as a leuco dye and an acidic developer such as a phenoliccompound. In cold, these components are a dark colored salt and uponheating they dissociate above a certain temperature to form a colourlessmixture. On cooling the dark colored salt forms again. The majordrawbacks are the poor photostability of the basic color former and theacidic developer and the color change may be retarded and such systemshave a reduced thermal stability which is a disadvantage in plasticarticles prepared by extrusion. A further drawback is that the system iscolored only in one state (at cold temperature).

The system according to this invention does not have these disadvantagesas the used compounds may have a greater photostability and less or noretarding of the color change. For instance, the color change is fullyreversible and there is essentially no fatigue after many hot-coldcycles. The system or compound according to this invention changes colorupon heating and turn back to the original color upon cooling. So atcold temperature the system or compound is in one chemical form and uponheating the system or compound changes color and is in another chemicalform. In the instant case, one form (at higher temperature) is a1,4-dihydroxy-anthraquinone derivative together with a2,2,6,6-tetramethylpiperidine derivative and the other form (at coldtemperature) is the corresponding salt formed by the correspondinganthraquinone anion and the 2,2,6,6-tetramethylpiperidinium cation. In acool surrounding, the color is, for example, blue or reddish blue whichturns upon heating, for example, to red or orange.1,4-dihydroxy-anthraquinone derivatives are thermally quite stable sothey can be extruded at high temperature which is required forincorporation into common thermoplastic polymers.

The present invention pertains in particular to a reversiblethermochromic system comprising

a) a compound of the formula (IA) or a tautomer thereof, ora compound of the formula (IB) or a tautomer thereof

whereinR₁ is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkylsubstituted by 1, 2 or 3 C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2or 3 C₁-C₄alkyl; or C₇-C₁₂phenylalkyl;R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ independently of one another are hydrogen, C₁-C₁₈alkyl,C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkyl substituted by 1, 2 or3 C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; andR is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkylsubstituted by 1, 2 or 3

C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; and

b) a compound containing a group of the formula

Examples of corresponding tautomers of the formula (IA) are

Examples of corresponding tautomers of the formula (IB) are

Examples of C₁-C₁₈ alkyl are methyl, ethyl, propyl, isopropyl, n-butyl,sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl,1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl,2-methylheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl,3-methylheptyl, n-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl,1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl,dodecyl, tetradecyl, hexadecyl and octadecyl.

Examples of C₂-C₁₈alkenyl are vinyl, allyl, butenyl, pentenyl, hexenyl,heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl,hexadecenyl and octadecenyl. The term alkenyl also comprises residueswith more than one double bond that may be conjugated or non-conjugated.Alkenyl with one double bond, in particular allyl, is preferred.

Examples of C₃-C₁₂cycloalkyl are cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cyclooctyl, cyclodecyl and cyclododecyl. Cyclohexyl ispreferred.

Examples of C₃-C₁₂cycloalkyl substituted by 1, 2 or 3 C₁-C₄alkyl aremethylcyclopentyl, dimethylcyclopentyl and methylcyclohexyl.

A preferred example of phenyl substituted by 1, 2 or 3 C₁-C₄alkyl ismethylphenyl.

A preferred example of C₇-C₉phenylalkyl is benzyl.

According to a preferred embodiment of the present invention

R₁ is C₈-C₁₈alkyl, allyl, cyclohexyl, phenyl or benzyl;R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ independently of one another are hydrogen, C₁-C₁₀alkyl, allyl,cyclohexyl, phenyl or benzyl; andR is C₈-C₁₈alkyl, allyl, cyclohexyl, phenyl or benzyl.

According to another preferred embodiment of the present invention

R₁ is C₈-C₁₈ alkyl or phenyl;R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ independently of one another are hydrogen or C₁-C₄alkyl; andR is C₈-C₁₈alkyl or phenyl.

According to a particularly preferred embodiment

R₁ is C₁₀-C₁₈ alkyl;R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ independently of one another are hydrogen or C₁-C₄alkyl; andR is C₁₀-C₁₈alkyl.

Suitable examples of component b) are listed below:

A compound of the formula (A-1)

wherein n₁ is a number from 2 to 50.

A compound of the formula (A-2)

wherein n₂ is a number from 2 to 50,A₅ is hydrogen or C₁-C₄alkyl,the radicals A₆ and A₇ independently of one another are C₁-C₄alkyl or agroup of the formula (a-I)

wherein A₈ is hydrogen; with the proviso that at least 50% of theradicals A₇ are a group of the formula (a-I).

A compound of the formula (B-1)

in whichE₁₁ is hydrogen,m₁ is 1, 2 or 4,if m₁ is 1, E₁₂ is C₁-C₂₅alkyl,if m₁ is 2, E₁₂ is C₁-C₁₄alkylene or a group of the formula (b-I)

wherein E₁₃ is C₁-C₁₀alkyl or C₂-C₁₀alkenyl, E₁₄ is C₁-C₁₀alkylene, andE₁₅ and E₁₆ independently of one another are C₁-C₄alkyl, cyclohexyl ormethylcyclohexyl, andif m₁ is 4, E₁₂ is C₄-C₁₀alkanetetrayl.

A compound of the formula (B-2)

in which two of the radicals E₁₇ are —COO—(C₁-C₂₀alkyl), andtwo of the radicals E₁₇ are a group of the formula (b-II)

with E₁₈ being hydrogen.

A compound of the formula (B-3)

in which E₁₉ and E₂₀ together form C₂-C₁₄alkylene,E₂₁ is hydrogen or a group —Z₁—COO—Z₂,Z₁ is C₂-C₁₄alkylene, andZ₂ is C₁-C₂₄alkyl, andE₂₂ is hydrogen.

A compound of the formula (B-4)

wherein the radicals E₂₃ are hydrogen,the radicals E₂₄ independently of one another are hydrogen orC₁-C₁₂alkyl, andE₂₅ is C₁-C₁₀alkylene or C₃-C₁₀alkylidene.

A compound of the formula (B-5)

wherein the radicals E₂₅ are hydrogen.

A compound of the formula (B-6)

in which E₂₇ is C₁-C₂₄alkyl, andE₂₈ is hydrogen.

A compound of the formula (B-7)

in which E₂₉, E₃₀ and E₃₁ independently of one another are a group ofthe formula (b-III)

wherein E₃₂ is hydrogen.

A compound of the formula (B-8)

whereinthe radicals E₃₃ are hydrogen,and E₃₄ is hydrogen, C₁-C₁₂alkyl or C₁-C₁₂alkoxy.

A compound of the formula (B-9)

wherein m₂ is 1, 2 or 3,E₃₅ is hydrogen, andwhen m₂ is 1, E₃₆ is a group

when m₂ is 2, E₃₆ is C₂-C₂₂alkylene, andwhen m₂ is 3, E₃₆ is a group of the formula (b-IV)

wherein the radicals E₃₇ independently of one another areC₂-C₁₂alkylene, andthe radicals E₃₈ independently of one another are C₁-C₁₂alkyl orC₅-C₁₂cycloalkyl.

A compound of the formula (B-10)

whereinthe radicals E₃₉ are hydrogen, andE₄₀ is C₂-C₂₂alkylene, C₅-C₇cycloalkylene,C₁-C₄alkylenedi(C₅-C₇cycloalkylene), phenylene orphenylenedi(C₁-C₄alkylene).

A compound of the formula (C-1)

in which R₃₀, R₃₂, R₃₃ and R₃₄ independently of one another arehydrogen, C₁-C₁₂alkyl, C₅-C₁₂cycloalkyl, C₁-C₄-alkyl-substitutedC₅-C₁₂cycloalkyl, phenyl, phenyl which is substituted by —OH and/orC₁-C₁₀alkyl; C₇-C₉phenylalkyl, C₇-C₉phenylalkyl which is substituted onthe phenyl radical by —OH and/or C₁-C₁₀alkyl; or a group of the formula(c-I)

R₃₁ is C₂-C₄alkylene, C₅-C₇cycloalkylene orC₁-C₄alkylenedi(C₅-C₇cycloalkylene), or the radicals R₃₀, R₃₁ and R₃₂,together with the nitrogen atoms to which they are bonded, perform a 5-to 10-membered heterocyclic ring, orR₃₃ and R₃₄, together with the nitrogen atom to which they are bonded,form a 5- to 10-membered heterocyclic ring,R₃₅ is hydrogen, andb₁ is a number from 2 to 50,with the proviso that at least one of the radicals R₃₀, R₃₂, R₃₃ and R₃₄is a group of the formula (c-I).

A compound of the formula (C-2)

wherein R₃₆ and R₄₀ independently of one another are hydrogen orC₁-C₁₂alkyl, R₃₇, R₃₈ and R₃₉ independently of one another areC₂-C₁₀alkylene, and X₁, X₂, X₃, X₄, X₅, X₆, X₇ and X₈ independently ofone another are a group of the formula (c-II),

in which R₄₁ is hydrogen, C₁-C₁₂alkyl, C₅-C₁₂cycloalkyl,C₁-C₄alkyl-substituted C₅-C₁₂cycloalkyl, phenyl, —OH— and/orC₁-C₁₀alkyl-substituted phenyl, C₇-C₉phenylalkyl, C₇-C₉phenylalkyl whichis substituted on the phenyl radical by —OH and/or C₁-C₁₀alkyl; or agroup of the formula (c-I) as defined above, andR₄₂ is hydrogen.

A compound of the formula (C-3)

in whichR₄₃ is C₁-C₁₀alkyl, C₅-C₁₂cycloalkyl, C₁-C₄alkyl-substitutedC₅-C₁₂cycloalkyl, phenyl or C₁-C₁₀alkyl-substituted phenyl,R₄₄ is C₃-C₁₀alkylene,R₄₅ is hydrogen, andb₂ is a number from 2 to 50.

A compound of the formula (C-4)

in whichR₄₆ and R₅₀ independently of one another are a direct bond or a—N(X₉)—CO—X₁₀—CO—N(X₁₁)— group, where X₉ and X₁₁ independently of oneanother are hydrogen, C₁-C₈alkyl, C₅-C₁₂cycloalkyl, phenyl,C₇-C₉phenylalkyl or a group of the formula (c-I),X₁₀ is a direct bond or C₁-C₄alkylene,R₄₇ is hydrogen,R₄₈, R₄₉, R₅₂ and R₅₃ independently of one another are hydrogen,C₁-C₃₀alkyl, C₅-C₁₂cycloalkyl or phenyl,R₅₁ is hydrogen, C₁-C₃₀alkyl, C₅-C₁₂cycloalkyl, phenyl, C₇-C₉phenylalkylor a group of the formula (c-I), andb₃ is a number from 1 to 50.

A compound of the formula (C-5)

in whichR₅₄, R₅₅, R₅₆, R₅₇ and R₅₈ independently of one another are a directbond or C₁-C₁₀alkylene,R₅₉ is hydrogen, andb₄ is a number from 1 to 50.

A compound of the formula (C-6-a)

wherein b₅ is a number from 2 to 20.

For the sterically hindered amines, the mentioned terms comprise, forinstance, the following meanings:

Examples of alkyl having up to 30 carbon atoms are methyl, ethyl,propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl,2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethyl-butyl,n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl,1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl,1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl,1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl,tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl,docosyl and triacontyl.

Examples of alkoxy having up to 18 carbon atoms are methoxy, ethoxy,propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy,heptoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy andoctadecyloxy. E₃₄ is preferably C₁-C₄alkoxy.

Examples of C₅-C₁₂cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl and cyclododecyl. C₅-C₈Cycloalkyl, especially cyclohexyl, ispreferred.

—OH— and/or C₁-C₁₀alkyl-substituted phenyl is for example methylphenyl,dimethylphenyl, trimethylphenyl, tert-butylphenyl or3,5-di-tert-butyl-4-hydroxyphenyl.

Examples of C₇-C₉phenylalkyl are benzyl and phenylethyl.

C₇-C₉Phenylalkyl which is substituted on the phenyl radical by —OHand/or by alkyl having up to 10 carbon atoms is for examplemethylbenzyl, dimethylbenzyl, trimethylbenzyl, tert-butylbenzyl or3,5-di-tert-butyl-4-hydroxybenzyl.

Examples of alkenyl having up to 10 carbon atoms are allyl, 2-methallyl,butenyl, pentenyl and hexenyl. Allyl is preferred. The carbon atom inposition 1 is preferably saturated.

C₁-C₈Alkanoyl, C₃-C₈alkenyl and benzoyl are preferred. Acetyl andacryloyl are especially preferred.

Examples of alkylene having up to 22 carbon atoms are methylene,ethylene, propylene, trimethylene, tetramethylene, pentamethylene,2,2-dimethyltrimethylene, hexamethylene, trimethylhexamethylene,octamethylene and decamethylene.

An example of C₃-C₁₀alkylidene is the group

An example of C₃-C₁₀alkanetetrayl is 1,2,3,4-butanetetrayl.

An example of C₅-C₇cycloalkylene is cyclohexylene.

An example of C₁-C₄alkylenedi(C₅-C₇cycloalkylene) ismethylenedicyclohexylene.

An example of phenylenedi(C₁-C₄alkylene) ismethylene-phenylene-methylene or ethylene-phenylene-ethylene.

Where the radicals R₃₀, R₃₁ and R₃₂, together with the nitrogen atoms towhich they are attached, form a 5- to 10-membered heterocyclic ring,this ring is for example

A 6-membered heterocyclic ring is preferred.

Where the radicals R₃₃ and R₃₄, together with the nitrogen atom to whichthey are attached, form a 5- to 10-membered heterocyclic ring, this ringis for example 1-pyrrolidyl, piperidino, morpholino, 1-piperazinyl,4-methyl-1-piperazinyl, 1-hexahydroazepinyl,5,5,7-trimethyl-1-homopiperazinyl or4,5,5,7-tetramethyl-1-homopiperazinyl. Morpholino is particularlypreferred.

One of the preferred definitions of R₄₈ and R₅₂ is phenyl.

R₅₅ is preferably a direct bond.n₁ and n₂ are preferably a number from 2 to 25, in particular 2 to 20.b₁ and b₂ are preferably a number from 2 to 25, in particular 2 to 20.b₃ and b₄ are preferably a number from 1 to 25, in particular 1 to 20.

The 2,2,6,6-tetramethylpiperidine derivatives described above areessentially known and commercially available. All of them can beprepared by known processes.

The preparation of the 2,2,6,6-tetramethylpiperidine derivatives whichcontain A in the denotation of the formula is disclosed for example inEP-A-28,318 and EP-A-1,803.

The preparation of the 2,2,6,6-tetramethylpiperidine derivatives whichcontain B in the denotation of the formula is disclosed for example inU.S. Pat. No. 5,679,733, U.S. Pat. No. 3,640,928, U.S. Pat. No.4,198,334, U.S. Pat. No. 5,204,473, U.S. Pat. No. 4,619,958, U.S. Pat.No. 4,110,306, U.S. Pat. No. 4,110,334, U.S. Pat. No. 4,689,416, U.S.Pat. No. 4,408,051, SU-A-768,175 (Derwent 88-138,751/20), U.S. Pat. No.5,049,604, U.S. Pat. No. 4,769,457, U.S. Pat. No. 4,356,307, U.S. Pat.No. 4,619,956, U.S. Pat. No. 5,182,390, GB-A-2,269,819, U.S. Pat. No.4,292,240, U.S. Pat. No. 5,026,849, U.S. Pat. No. 5,071,981, U.S. Pat.No. 4,547,538 and U.S. Pat. No. 4,976,889.

The preparation of the 2,2,6,6-tetramethylpiperidine derivatives whichcontain C in the denotation of the formula is disclosed for example inU.S. Pat. No. 4,086,204, U.S. Pat. No. 6,046,304, U.S. Pat. No.4,331,586, U.S. Pat. No. 4,108,829, U.S. Pat. No. 5,051,458,WO-A-94/12,544 (Derwent 94-177,274/22), DD-A-262,439 (Derwent89-122,983/17), U.S. Pat. No. 4,857,595, U.S. Pat. No. 4,529,760 andU.S. Pat. No. 4,477,615 and CAS 136, 504-96-6.

The following commercially available products are suitable as stericallyhindered amines: FERRO® AM 806 (CAS 70800-09-8), DASTIB® 845 (CAS24860-22-8), TINUVIN® 770 (CAS 58829-07-9), ADK STAB® LA 57 (CAS64022-61-3), ADK STAB® LA 67 (CAS 100631-43-4), HOSTAVIN® N 20 (CAS64338-16-5), HOSTAVIN® N 24 (CAS 85099-51-0 and 85099-50-9), SANDUVOR®3050 (CAS 85099-51-0 and 85099-50-9), DIACETAM® 5 (CAS 76505-58-3),SUMISORB® TM 61 (CAS 84214-94-2), UVINUL® 4049 (CAS 109423-00-9),GOODRITE® UV 3034 (CAS 71029-16-8), GOODRITE® UV 3150 (CAS 96204-36-3),GOODRITE® 3110 x 128, UVINUL® 4050 H (CAS 124172-53-8), CHIMASSORB® 944(CAS 71878-19-8), CHIMASSORB® 2020 (CAS 192268-64-7), CYASORB® UV 3346(CAS 82451-48-7), DASTIB® 1082 (CAS 113169-96-3), UVASIL® 299 (CAS164648-93-5), UVASIL® 125 (CAS 164648-93-5), UVASIL® 2000 (CAS164648-93-5), UVINUL® 5050 H (CAS 152261-33-1 and 199237-39-3),LICHTSCHUTZSTOFF® UV 31, LUCHEM® HA B 18, ADK STAB® LA 68 (CAS100631-44-5) or UVASORB® HA 88 (CAS 136504-96-6). GOODRITE® 3110 x 128is of formula

The meanings of the terminal groups which saturate the free valences inthe compounds of the formulae (A-1), (A-2), (C-1), (C-3), (C-4), (C-5)and (C-6-a) depend on the processes used for their preparation. Theterminal groups can also be modified after the preparation of thecompounds.

In the compounds of the formula (A-1), the terminal group bonded to thedimethylene radical can be, for example, —OH, and the terminal groupbonded to the oxygen can be, for example, hydrogen. The terminal groupscan also be polyether radicals.

In the compounds of the formula (A-2), the end group bonded to the —CH₂—residue can be, for example, hydrogen and the end group bonded to the—CH(CO₂A₇) residue can be, for example, —CH═CH—COOA₇.

If the compounds of the formula (C-1) are prepared by reacting acompound of the formula

in which X is, for example, halogen, in particular chlorine, and R₃₃ andR₃₄ are as defined above, with a compound of the formula

in which R₃₀, R₃₁ and R₃₂ are as defined above, the terminal groupbonded to the diamino radical is hydrogen or

and the terminal group bonded to the triazine radical is X or

If X is halogen, it is advantageous to replace this, for example, by —OHor an amino group when the reaction is complete. Examples of aminogroups which may be mentioned are pyrrolidin-1-yl, morpholino, —NH₂,—N(C₁-C₈)alkyl)₂ and —NR(C₁-C₈alkyl), in which R is hydrogen or a groupof the formula (c-I).

The compounds of the formula (C-1) also cover compounds of the formula

wherein R₃₀, R₃₁, R₃₂, R₃₃, R₃₄ and b₁ are as defined above and R₃₃* hasone of the meanings of R₃₃ and R₃₄* has one of the meanings of R₃₄.

One of the particularly preferred compounds of the formula (C-1) is

The preparation of this compound is described in Example 10 of U.S. Pat.No. 6,046,304.

In the compounds of the formula (C-3), the terminal group bonded to thesilicon atom can be, for example, (R₄₃)₃Si—O—, and the terminal groupbonded to the oxygen can be, for example, —Si(R₄₃)₃.

The compounds of the formula (C-3) can also be in the form of cycliccompounds If b₂ is a number from 3 to 10, i.e. the free valences shownin the structural formula then form a direct bond.

In the compounds of the formula (C-4), the terminal group bonded to the2,5-dioxopyrrolidine ring is, for example, hydrogen, and the terminalgroup bonded to the —C(R₅₂)(R₅₃)— radical is, for example,

In the compounds of the formula (C-5), the terminal group bonded to thecarbonyl radical is, for example,

and the terminal group bonded to the oxygen radical is, for example,

In the compounds of the formula (C-6-a), the terminal group bonded tothe triazine radical is, for example, Cl or a

group, and the terminal group bonded to the amino radical is, forexample, hydrogen or a

group.

Of interest is a sterically hindered amine that corresponds to acompound of the formula (A-1) or (A-2);

wherein n₁ and n₂ are a number from 2 to 20, andat least 50% of the radicals A₇ are a group of the formula (a-I)

wherein A₈ is hydrogen;and the remaining radicals A₇ are ethyl.

For example, the sterically hindered amine is a compound of the formula(B-1-a), (B-1-b), (B-1-c), (B-1-d), (B-2-a), (B-3-a), (B-3-b), (B-4-a),(B-4-b), (B-5), (B-6-a), (B-7), (B-8-a), (B-9-a), (B-9-b), (B-9-c) or(B-10-a);

wherein E₁₁ is hydrogen;

in which two of the radicals E₁₇ are —COO—C₁₃H₂₇ and two of the radicalsE₁₇ are

and E₁₈ is hydrogen;

wherein E₂₂ is hydrogen;

wherein E₂₃ hydrogen;

wherein E₂₆ is hydrogen;

wherein E₂₈ is hydrogen;

in which E₂₉, E₃₀ and E₃₁ independently of one another are a group ofthe formula (b-III)

wherein E₃₂ is hydrogen;

wherein E_(n) is hydrogen;

wherein E₃₅ is hydrogen;

wherein E₃₉ is hydrogen.

For instance, the sterically hindered amine is a compound of the formula(C-1-a), (C-1-b), (C-1-c), (C-1-d), (C-2-a), (C-3-a), (C-4-a), (C-4-b),(C-4-c), (C-5-a) or (C-6-a);

wherein b₁ is a number from 2 to 20 and R₃₅ is hydrogen;

wherein R₄₂ is hydrogen,

wherein b₂ is a number from 2 to 20 and R₄₅ is hydrogen;

wherein b₃ is a number from 1 to 20 and R₄₇ is hydrogen;

wherein b₅ is a number from 2 to 20.

Of interest are the following commercially available compounds:

TINUVIN® 770 corresponds to the compound of the formula (B-1-b) whereinE₁₁ is hydrogen.

ADK STAB® LA 57 corresponds to the compound of the formula (B-1-d)wherein E₁₁ is hydrogen.

ADK STAB® LA 67 corresponds to the compound of the formula (B-2-a)wherein E₁₈ is hydrogen.

HOSTAVIN® N 24 corresponds to the compound of the formula (B-3-b)wherein E₂₂ is hydrogen.

SANDUVOR® 3050 corresponds to the compound of the formula (B-3-b-1)shown below, wherein E₂₂ is hydrogen.

DIACETAM® 5 corresponds to the compound of the formula (B-4-a) whereinE₂₃ is hydrogen.

SUMISORB TM 61 corresponds to the compound of the formula (B-4-b)wherein E₂₃ is hydrogen.

UVINUL 4049 corresponds to the compound of the formula (B-5) wherein E₂₅is hydrogen.

GOODRITE® 3034 corresponds to the compound of the formula (B-9-b)wherein E₃₅ is hydrogen.

GOODRITE® 3150 corresponds to the compound of the formula (B-9-c)wherein E₃₅ is hydrogen.

CHIMASSORB® 944 corresponds to the compound of the formula (C-1-a)wherein R₃₅ is hydrogen.

CHIMASSORB® 2020 corresponds to the compound of the formula (C-1-b)wherein R₃₅ is hydrogen.

DASTIB® 1082 corresponds to the compound of the formula (C-1-c) whereinR₃₅ is hydrogen.

CYASORB® UV 3346 corresponds to the compound of the formula (C-1-d)wherein R₃₅ is hydrogen.

UVASIL® 299 corresponds to the compound of the formula (C-3-a) whereinR₄₅ is hydrogen.

UVINUL® 5050 H corresponds to the compound of the formula (C-4-a)wherein R₄₇ is hydrogen.

LICHTSCHUTZSTOFF® UV 31 corresponds to the compound of the formula(C-4-b) wherein R₄₇ is hydrogen.

LUCHEM® HA B 18 corresponds to the compound of the formula (C-4-c)wherein R₄₇ is hydrogen.

ADK STAB® LA 68 corresponds to the compound of the formula (C-5-a)wherein R₅₉ is hydrogen.

UVASORB® HA 88 corresponds to the compound of the formula (C-6-a).

The compound of the formula (B-3-b-1) has the following structure:

Of special interest are the compounds of the formulae (C-1-a), (C-1-b),(C-1-c), (C-1-d) and (C-6-a), in particular (C-1-a) and (C-1-b).

A reversible thermochromic system wherein

component a) is a compound of the formula

andcomponent b) is a compound of the formula (C-1-a) or (C-1-b)

wherein b₁ is a number from 2 to 20,is preferred.

The ratio of component a) to component b) is preferably 2:1 to 1:100 byweight, more preferably 1:1 to 1:20 by weight, most preferably 1:2 to1:16 by weight, for example 1:3 to 1:6 by weight.

A further embodiment of this invention is a composition containing

a carrier selected from the group consisting of a polymer, a solvent anda wax; anda reversible thermochromic system as defined above.

The ratio of the carrier to the reversible thermochromic system ispreferably 10000:1 to 1:1, more preferably 5000:1 to 2:1, mostpreferably 1000:1 to 5:1.

The carrier material is for example also a coating or an ink.

Examples of polymers suitable as carrier material are:

1. Polymers of monoolefins and diolefins, for example polypropylene,polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymersof cycloolefins, for instance of cyclopentene or norbornene,polyethylene (which optionally can be crosslinked), for example highdensity polyethylene (HDPE), high density and high molecular weightpolyethylene (HDPE-HMW), high density and ultrahigh molecular weightpolyethylene (HDPE-UHMW), medium density polyethylene (MDPE), lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE),(VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, preferably polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

-   -   a) radical polymerisation (normally under high pressure and at        elevated temperature).    -   b) catalytic polymerisation using a catalyst that normally        contains one or more than one metal of groups IVb, Vb, VIb or        VIII of the Periodic Table. These metals usually have one or        more than one ligand, typically oxides, halides, alcoholates,        esters, ethers, amines, alkyls, alkenyls and/or aryls that may        be either π- or σ-coordinated. These metal complexes may be in        the free form or fixed on substrates, typically on activated        magnesium chloride, titanium(III) chloride, alumina or silicon        oxide. These catalysts may be soluble or insoluble in the        polymerization medium. The catalysts can be used by themselves        in the polymerization or further activators may be used,        typically metal alkyls, metal hydrides, metal alkyl halides,        metal alkyl oxides or metal alkyloxanes, said metals being        elements of groups Ia, IIa and/or IIIa of the Periodic Table.        The activators may be modified conveniently with further ester,        ether, amine or silyl ether groups. These catalyst systems are        usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta),        TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1), for example mixtures ofpolypropylene with polyisobutylene, polypropylene with polyethylene (forexample PP/HDPE, PP/LDPE) and mixtures of different types ofpolyethylene (for example LDPE/HDPE).

3. Copolymers of monoolefins and diolefins with each other or with othervinyl monomers, for example ethylene/propylene copolymers, linear lowdensity polyethylene (LLDPE) and mixtures thereof with low densitypolyethylene (LDPE), propylene/but-1-ene copolymers,propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,ethylene/hexene copolymers, ethylene/methylpentene copolymers,ethylene/heptene copolymers, ethylene/octene copolymers,ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers(e.g. ethylene/norbornene like COC), ethylene/1-olefins copolymers,where the 1-olefin is generated in-situ; propylene/butadiene copolymers,isobutylene/isoprene copolymers, ethylene/vinylcyclohexene copolymers,ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylatecopolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acidcopolymers and their salts (ionomers) as well as terpolymers of ethylenewith propylene and a diene such as hexadiene, dicyclopentadiene orethylidene-norbornene; and mixtures of such copolymers with one anotherand with polymers mentioned in 1) above, for examplepolypropylene/ethylenepropylene copolymers, LDPE/ethylene-vinyl acetatecopolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA),LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbonmonoxide copolymers and mixtures thereof with other polymers, forexample polyamides.

4. Hydrocarbon resins (for example C₅-C₉) including hydrogenatedmodifications thereof (e.g. tackifiers) and mixtures of polyalkylenesand starch. Homopolymers and copolymers from 1.)-4.) may have anystereostructure including syndiotactic, isotactic, hemi-isotactic oratactic; where atactic polymers are preferred. Stereoblock polymers arealso included.

5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

6. Aromatic homopolymers and copolymers derived from vinyl aromaticmonomers including styrene, α-methylstyrene, all isomers of vinyltoluene, especially p-vinyltoluene, all isomers of ethyl styrene, propylstyrene, vinyl biphenyl, vinyl naphthalene, and vinyl anthracene, andmixtures thereof. Homopolymers and copolymers may have anystereostructure including syndiotactic, isotactic, hemi-isotactic oratactic; where atactic polymers are preferred. Stereoblock polymers arealso included.

6a. Copolymers including aforementioned vinyl aromatic monomers andcomonomers selected from ethylene, propylene, dienes, nitriles, acids,maleic anhydrides, maleimides, vinyl acetate and vinyl chloride oracrylic derivatives and mixtures thereof, for example styrene/butadiene,styrene/acrylonitrile, styrene/ethylene (interpolymers), styrene/alkylmethacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkylmethacrylate, styrene/maleic anhydride, styrene/acrylonitrile/methylacrylate; mixtures of high impact strength of styrene copolymers andanother polymer, for example a polyacrylate, a diene polymer or anethylene/propylene/diene terpolymer; and block copolymers of styrenesuch as styrene/butadiene/styrene, styrene/isoprene/styrene,styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene.

6b. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6.), especially includingpolycyclohexylethylene (PCHE) prepared by hydrogenating atacticpolystyrene, often referred to as polyvinylcyclohexane (PVCH).

6c. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6a.).

Homopolymers and copolymers may have any stereostructure includingsyndiotactic, isotactic, hemi-isotactic or atactic; where atacticpolymers are preferred. Stereoblock polymers are also included.

7. Graft copolymers of vinyl aromatic monomers such as styrene orα-methylstyrene, for example styrene on polybutadiene, styrene onpolybutadiene-styrene or polybutadiene-acrylonitrile copolymers; styreneand acrylonitrile (or methacrylonitrile) on polybutadiene; styrene,acrylonitrile and methyl methacrylate on polybutadiene; styrene andmaleic anhydride on polybutadiene; styrene, acrylonitrile and maleicanhydride or maleimide on polybutadiene; styrene and maleimide onpolybutadiene; styrene and alkyl acrylates or methacrylates onpolybutadiene; styrene and acrylonitrile on ethylene/propylene/dieneterpolymers; styrene and acrylonitrile on polyalkyl acrylates orpolyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadienecopolymers, as well as mixtures thereof with the copolymers listed under6), for example the copolymer mixtures known as ABS, MBS, ASA or AESpolymers.

8. Halogen-containing polymers such as polychloroprene, chlorinatedrubbers, chlorinated and brominated copolymer of isobutylene-isoprene(halobutyl rubber), chlorinated or sulfochlorinated polyethylene,copolymers of ethylene and chlorinated ethylene, epichlorohydrin homo-and copolymers, especially polymers of halogen-containing vinylcompounds, for example polyvinyl chloride, polyvinylidene chloride,polyvinyl fluoride, polyvinylidene fluoride, as well as copolymersthereof such as vinyl chloride/vinylidene chloride, vinyl chloride/vinylacetate or vinylidene chloride/vinyl acetate copolymers.

9. Polymers derived from α,β-unsaturated acids and derivatives thereofsuch as polyacrylates and polymethacrylates; polymethyl methacrylates,polyacrylamides and polyacrylonitriles, impact-modified with butylacrylate.

10. Copolymers of the monomers mentioned under 9) with each other orwith other unsaturated monomers, for example acrylonitrile/butadienecopolymers, acrylonitrile/alkyl acrylate copolymers,acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halidecopolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

11. Polymers derived from unsaturated alcohols and amines or the acylderivatives or acetals thereof, for example polyvinyl alcohol, polyvinylacetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate,polyvinyl butyral, polyallyl phthalate or polyallyl melamine; as well astheir copolymers with olefins mentioned in 1) above.

12. Homopolymers and copolymers of cyclic ethers such as polyalkyleneglycols, polyethylene oxide, polypropylene oxide or copolymers thereofwith bisglycidyl ethers.

13. Polyacetals such as polyoxymethylene and those polyoxymethyleneswhich contain ethylene oxide as a comonomer; polyacetals modified withthermoplastic polyurethanes, acrylates or MBS.

14. Polyphenylene oxides and sulfides, and mixtures of polyphenyleneoxides with styrene polymers or polyamides.

15. Polyurethanes derived from hydroxyl-terminated polyethers,polyesters or polybutadienes on the one hand and aliphatic or aromaticpolyisocyanates on the other, as well as precursors thereof.

16. Polyamides and copolyamides derived from diamines and dicarboxylicacids and/or from aminocarboxylic acids or the corresponding lactams,for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12,4/6, 12/12, polyamide 11, polyamide 12, aromatic polyamides startingfrom m-xylene diamine and adipic acid; polyamides prepared fromhexamethylenediamine and isophthalic or/and terephthalic acid and withor without an elastomer as modifier, for examplepoly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenyleneisophthalamide; and also block copolymers of the aforementionedpolyamides with polyolefins, olefin copolymers, ionomers or chemicallybonded or grafted elastomers; or with polyethers, e.g. with polyethyleneglycol, polypropylene glycol or polytetramethylene glycol; as well aspolyamides or copolyamides modified with EPDM or ABS; and polyamidescondensed during processing (RIM polyamide systems).

17. Polyureas, polyimides, polyamide-imides, polyetherimids,polyesterimids, polyhydantoins and polybenzimidazoles.

18. Polyesters derived from dicarboxylic acids and diols and/or fromhydroxycarboxylic acids or the corresponding lactones, for examplepolyethylene terephthalate, polybutylene terephthalate,poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene naphthalate(PAN) and polyhydroxybenzoates, as well as block copolyether estersderived from hydroxyl-terminated polyethers; and also polyestersmodified with polycarbonates or MBS.

19. Polycarbonates and polyester carbonates.

20. Polyketones.

21. Polysulfones, polyether sulfones and polyether ketones.

22. Crosslinked polymers derived from aldehydes on the one hand andphenols, ureas and melamines on the other hand, such asphenol/formaldehyde resins, urea/formaldehyde resins andmelamine/formaldehyde resins.

23. Drying and non-drying alkyd resins.

24. Unsaturated polyester resins derived from copolyesters of saturatedand unsaturated dicarboxylic acids with polyhydric alcohols and vinylcompounds as crosslinking agents, and also halogen-containingmodifications thereof of low flammability.

25. Crosslinkable acrylic resins derived from substituted acrylates, forexample epoxy acrylates, urethane acrylates or polyester acrylates.

26. Alkyd resins, polyester resins and acrylate resins crosslinked withmelamine resins, urea resins, isocyanates, isocyanurates,polyisocyanates or epoxy resins.

27. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic,heterocyclic or aromatic glycidyl compounds, e.g. products of diglycidylethers of bisphenol A and bisphenol F, which are crosslinked withcustomary hardeners such as anhydrides or amines, with or withoutaccelerators.

28. Natural polymers such as cellulose, rubber, gelatin and chemicallymodified homologous derivatives thereof, for example cellulose acetates,cellulose propionates and cellulose butyrates, or the cellulose etherssuch as methyl cellulose; as well as rosins and their derivatives.

29. Blends of the aforementioned polymers (polyblends), for examplePP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR,PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 andcopolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or PBT/PET/PC.

For instance, the polymer is an organic polymer such as a syntheticorganic polymer, especially a thermoplastic polymer.

Preferably, the polymer is such as mentioned under items 1-3, inparticular polypropylene, polypropylene copolymer, polyethylene orpolyethylene copolymer, especially polypropylene or polyethylene.

Incorporation into the organic polymers can be effected, for example, bymixing in or applying to the components of the reversible thermochromicsystem as defined above and, if desired, further additives by themethods which are customary in the art. The incorporation can take placeprior to or during the shaping operation, or by applying the dissolvedor dispersed components of the reversible thermochromic system to thepolymer, with or without subsequent evaporation of the solvent. In thecase of elastomers, these can also be stabilized as lattices. A furtherpossibility for incorporating the compounds mentioned above intopolymers is to add them before, during or directly after thepolymerization of the corresponding monomers or prior to crosslinking.In this context the compounds mentioned above can be added as it is orelse in encapsulated form (for example in waxes, oils or polymers).

The compounds mentioned herein can also be added in the form of amasterbatch containing said compound in a concentration, for example, offrom 2.5 to 25% by weight to the carrier material.

The compounds mentioned herein can judiciously be incorporated by thefollowing methods:

-   -   as emulsion or dispersion (e.g. to lattices or emulsion        polymers),    -   as a dry mixture during the mixing in of additional components        or polymer mixtures,    -   by direct introduction into the processing apparatus (e.g.        extruders, internal mixers, etc),    -   as solution or melt.

The components of the reversible thermochromic system, with or withoutfurther additives, can also be sprayed onto the carrier material such asplastic article, fiber, film, paper or coating. The system is able todilute other additives (for example the conventional additives indicatedbelow) or their melts so that they too can be sprayed together withthese additives onto the carrier material.

Of interest is also a reversible thermochromic composition as definedabove, comprising further additives.

Preferably, the further additives are

antioxidants, UV-absorbers, light stabilizers, metal deactivators,processing stabilizers, thiosynergists, peroxide scavengers, oxygenscavengers, basic co-stabilizers, nucleating agents, fillers,reinforcing agents, flameproofing agents and/or additional colorantswith the proviso that the additional colorants do not suppress and donot mask the thermochromic effect.

Most preferably, the further additives are

phenolic antioxidants, aminic antioxidants, phosphites, phosphonites,hydroxylamines, nitrones, benzofuranones, indolinones,2-(2-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones,2-(2-hydroxyphenyl)-1,3,5-triazines, oxamides, sterically hinderedamines, pigments and/or dyes.

General examples of suitable additives are:

1. Antioxidants

1.1. Alkylated monophenols, for example2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol,2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are linearor branched in the side chains, for example,2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1′-methylundec-1-yl)phenol,2,4-dimethyl-6-(1′-methylheptadec-1′-yl)phenol,2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol and mixtures thereof.1.2. Alkylthiomethylphenols, for example2,4-dioctylthiomethyl-6-tert-butylphenol,2,4-dioctylthiomethyl-6-methylphenol,2,4-dioctylthiomethyl-6-ethylphenol,2,6-di-dodecylthiomethyl-4-nonylphenol.1.3. Hydroquinones and alkylated hydroquinones, for example2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone,2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenylstearate, bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.1.4. Tocopherols, for example α-tocopherol, β-tocopherol, -tocopherol,-tocopherol and mixtures thereof (vitamin E).1.5. Hydroxylated thiodiphenyl ethers, for example 2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol),4,4′-thiobis(6-tert-butyl-3-methylphenol),4,4′-thiobis(6-tert-butyl-2-methylphenol),4,4′-thiobis(3,6-di-sec-amylphenol),4,4′-bis(2,6-dimethyl-4-hydroxyphenyl)disulfide.1.6. Alkylidenebisphenols, for example 2,2′-methylenebis(6-tert-butyl-4-methylphenol),2,2′-methylenebis(6-tert-butyl-4-ethylphenol),2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol],2,2′-methylenebis(4-methyl-6-cyclohexylphenol),2,2′-methylenebis(6-nonyl-4-methylphenol),2,2′-methylenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol],4,4′-methylenebis(2,6-di-tert-butylphenol),4,4′-methylenebis(6-tert-butyl-2-methylphenol),1,1-bis(5-tertbutyl-4-hydroxy-2-methylphenyl)butane,2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane,ethylene glycol bis[3,3-bis(3′-tertbutyl-4′-hydroxyphenyl)butyrate],bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene,bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane,2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane,1,1,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.1.7. O-, N- and S-benzyl compounds, for example 3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether,octadecyl-4-hydroxy-3,5-dimethyl benzylmercaptoacetate,tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate,tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine,bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide,isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.1.8. Hydroxybenzylated malonates, for exampledioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate,di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate,didodecylmercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.1.9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.1.10. Triazine compounds, for example2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,2,4,6-tris-(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine,1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.1.11. Benzylphosphonates, for exampledimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate,diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, thecalcium salt of the monoethyl ester of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.1.12. Acylaminophenols, for example 4-hydroxylauranilide,4-hydroxystearanilide, octylN-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.1.13. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol,i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.1.14. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acidwith mono- or polyhydric alcohols, e.g. with methanol, ethanol,n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethyleneglycol, diethylene glycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis-(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane;3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]-undecane.1.15. Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, tri-ethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono-or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.1.17. Amides of 6-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g.N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamide,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamide,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazide,N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide(Naugard®XL-1, supplied by Uniroyal).1.18. Ascorbic acid (vitamin C)1.19. Aminic antioxidants, for exampleN,N′-di-isopropyl-p-phenylenediamine,N,N′-di-sec-butyl-p-phenylenediamine,N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine,N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine,N,N′-bis(1-methylheptyl)-p-phenylenediamine,N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine,N,N′-bis(2-naphthyl)-p-phenylenediamine,N-isopropyl-N′-phenyl-p-phenylenediamine,N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine,N-cyclohexyl-N′-phenyl-p-phenylenediamine,4-(p-toluenesulfamoyl)diphenylamine,N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine,N-allyldiphenylamine, 4-isopropoxydiphenylamine,N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine,N-phenyl-2-naphthylamine, octylated diphenylamine, for examplep,p′-di-tert-octyldiphenylamine, 4-n-butyl-aminophenol,4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol,4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine,2,6-di-tert-butyl-4-dimethylaminomethylphenol,2,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane,N,N,N′,N′-tetra-methyl-4,4′-diaminodiphenylmethane,1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane,(o-tolyl)biguanide, bis[4-(1,3′-dimethylbutyl)phenyl]amine,tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- anddialkylated tert-butyl/tert-octyldiphenylamines, a mixture of mono- anddialkylated nonyldiphenylamines, a mixture of mono- and dialkylateddodecyldiphenylamines, a mixture of mono- and dialkylatedisopropyl/isohexyl-diphenylamines, a mixture of mono- and dialkylatedtert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine,phenothiazine, a mixture of mono- and dialkylatedtert-butyl/tert-octylphenothiazines, a mixture of mono- and dialkylatedtert-octyl-phenothiazines, N-allylphenothiazine,N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene.

2. UV Absorbers and Light Stabilizers

2.1. 2-(2′-Hydroxyphenyl)benzotriazoles, for example2-(2′-hydroxy-5′-methylphenyl)-benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chloro-benzotriazole,2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole,2-(3′-tert-butyl-Z-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)-carbonylethyl]-2′-hydroxyphenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole,2-(3′-tert-butyl-5′42-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole,2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,2,2′-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol];the transesterification product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazolewith polyethylene glycol 300; [R—CH₂CH₂—COO—CH₂CH₂₂, whereR=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-ylphenyl,2-[2′-hydroxy-3′-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)-phenyl]-benzotriazole;2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)-phenyl]benzotriazole.2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxyand 2′-hydroxy-4,4′-dimethoxy derivatives.2.3. Esters of substituted and unsubstituted benzoic acids, for example4-tert-butyl-phenyl salicylate, phenyl salicylate, octylphenylsalicylate, dibenzoyl resorcinol, bis(4-tert-butylbenzoyl)resorcinol,benzoyl resorcinol, 2,4-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate.2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctylα-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methylα-cyano-β-methyl-p-methoxycinnamate, butylα-cyano-β-methyl-p-methoxy-cinnamate, methylα-carbomethoxy-p-methoxycinnamate,N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline, neopentyltetra(α-cyano-β,β-di-phenylacrylate.2.5. Nickel compounds, for example nickel complexes of2,2′-thio-bis[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or1:2 complex, with or without additional ligands such as n-butylamine,triethanolamine or N-cyclohexyldiethanolamine, nickeldibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g. themethyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonicacid, nickel complexes of ketoximes, e.g. of2-hydroxy-4-methylphenylundecylketoxime, nickel complexes of1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additionalligands.2.6. Sterically hindered amines, for examplebis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(2,2,6,6-tetramethyl-4-piperidyl)succinate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, linear or cyclic condensates ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-triazine,tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cycliccondensates ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane, the condensate of2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, amixture of 4-hexadecyloxy- and4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensate ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensate of1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine aswell as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No.[136504-96-6]); a condensate of 1,6-hexanediamine and2,4,6-trichloro-1,3,5-triazine as well as N,N-dibutylamine and4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [192268-64-7]);N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide,N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide,2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, areaction product of7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro-[4,5]decaneand epichlorohydrin,1,1-bis(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene,N,N′-bis-formyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexa-methylenediamine,a diester of 4-methoxymethylenemalonic acid with1,2,2,6,6-pentamethyl-4-hydroxypiperidine,poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, areaction product of maleic acid anhydride-α-olefin copolymer with2,2,6,6-tetramethyl-4-aminopiperidine or1,2,2,6,6-pentamethyl-4-aminopiperidine,2,4-bis[N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)-N-butylamino]-6-(2-hydroxyethyl)amino-1,3,5-triazine,1-(2-hydro-oxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine,5-(2-ethylhexanoyl)-oxymethyl-3,3,5-trimethyl-2-morpholinone, Sanduvor(Clariant; CAS Reg. No. 106917-31-1],5-(2-ethylhexanoyl)oxymethyl-3,3,5-trimethyl-2-morpholinone, thereaction product of2,4-bis-[(1-cyclohexyloxy-2,2,6,6-piperidine-4-yl)butylamino]-6-chloro-s-triazinewith N,N′-bis(3-aminopropyl)ethylenediamine),1,3,5-tris(N-cyclohexyl-N-(2,2,6,6-tetramethylpiperazine-3-one-4-yl)amino)-s-triazine,1,3,5-tris(N-cyclohexyl-N-(1,2,2,6,6-pentamethylpiperazine-3-one-4-yl)-amino)-s-triazine.2.7. Oxamides, for example 4, 4′-dioctyloxyoxanilide,2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide,2,2′-didodecyloxy-5,5′-di-tert-butoxan Hide, 2-ethoxy-2′-ethyloxanilide,N,N′-bis(3-dimethylaminopropyl)oxamide,2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixture with2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide, mixtures of o- andp-methoxy-disubstituted oxanilides and mixtures of o- andp-ethoxy-disubstituted oxanilides.2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyl-oxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine,2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl-phenyl)-1,3,5-triazine,2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine,2-(2-hydro-oxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine,2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine,2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine,2-[2-hydroxy-4,3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(4-[2-ethylhexyloxy]-2-hydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine.3. Metal deactivators, for example N,N′-diphenyloxamide,N-salicylal-N′-salicyloyl hydrazine, N,N′-bis(salicyloyl)hydrazine,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl dihydrazide,oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide,N,N′-diacetyladipoyl dihydrazide, N,N′-bis(salicyloyl)oxalyldihydrazide, N,N′-bis(salicyloyl)thiopropionyl dihydrazide.4. Phosphites and phosphonites, for example triphenyl phosphite,diphenylalkyl phosphites, phenyldialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite,distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, diisodecyl pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,bis(2,4-dicumylphenyl)pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,diisodecyloxypentaerythritol diphosphite,bis(2,4-di-tert-butyl-6-methylphenyl)-pentaerythritol diphosphite,bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearylsorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)4,4′-biphenylene diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin,bis(2,4-di-tertbutyl-6-methylphenyl)methyl phosphite,bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite,6-fluoro-2,4,8,10-tetra-tert-butyl-[2-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin,2,2′,2″-nitrilo-[triethyltris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite],2-ethylhexyl(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite,5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphirane.

The following phosphites are especially preferred:

Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos® 168, Ciba SpecialtyChemicals Inc.), tris(nonylphenyl)phosphite,

5. Hydroxylamines, for example N,N-dibenzylhydroxylamine,N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine,N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine,N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine,N-hexadecyl-N-octadecylhydroxy-ylamine,N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derivedfrom hydrogenated tallow amine.6. Nitrones, for example, N-benzyl-alpha-phenylnitrone,N-ethyl-alpha-methylnitrone, N-octyl-alpha-heptylnitrone,N-lauryl-alpha-undecylnitrone, N-tetradecyl-alpha-tridecylnnitrone,N-hexadecyl-alpha-pentadecylnitrone,N-octadecyl-alpha-heptadecylnitrone,N-hexadecyl-alpha-heptadecylnitrone,N-ocatadecyl-alpha-pentadecylnitrone,N-heptadecyl-alpha-hepta-decylnitrone,N-octadecyl-alpha-hexadecylnitrone, nitrone derived fromN,N-dialkylhydroxyl-amine derived from hydrogenated tallow amine.7. Thiosynergists, for example dilauryl thiodipropionate, distearylthiodipropionate, distearyl thiodipropionate or distearyl disulfide.8. Peroxide scavengers, for example esters of β-thiodipropionic acid,for example the lauryl, stearyl, myristyl or tridecyl esters,mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zincdibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritoltetrakis(β-dodecylmercapto)propionate.9. Polyamide stabilizers, for example copper salts in combination withiodides and/or phosphorus compounds and salts of divalent manganese.10. Basic co-stabilizers, for example melamine, polyvinylpyrrolidone,dicyandiamide, triallyl cyanurate, urea derivatives, hydrazinederivatives, amines, polyamides, polyurethanes, alkali metal salts andalkaline earth metal salts of higher fatty acids, for example calciumstearate, zinc stearate, magnesium behenate, magnesium stearate, sodiumricinoleate and potassium palmitate, antimony pyrocatecholate or zincpyrocatecholate.11. Nucleating agents, for example inorganic substances, such as talcum,metal oxides, such as titanium dioxide or magnesium oxide, phosphates,carbonates or sulfates of, preferably, alkaline earth metals; organiccompounds, such as mono- or polycarboxylic acids and the salts thereof,e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodiumsuccinate or sodium benzoate; polymeric compounds, such as ioniccopolymers (ionomers). Especially preferred are1,3:2,4-bis(3′,4′-dimethylbenzylidene)sorbitol,1,3:2,4-di(paramethyl-dibenzylidene)sorbitol, and1,3:2,4-di(benzylidene)sorbitol.12. Fillers and reinforcing agents, for example calcium carbonate,silicates, glass fibres, glass beads, asbestos, talc, kaolin, mica,barium sulfate, metal oxides and hydroxides, carbon black, graphite,wood flour and flours or fibers of other natural products, syntheticfibers.13. Other additives, for example plasticisers, lubricants, emulsifiers,pigments, rheology additives, catalysts, flow-control agents, opticalbrighteners, flameproofing agents, antistatic agents and blowing agents.14. Benzofuranones and indolinones, for example those disclosed in U.S.Pat. No. 4,325,863; U.S. Pat. No. 4,338,244; U.S. Pat. No. 5,175,312;U.S. Pat. No. 5,216,052; U.S. Pat. No. 5,252,643; DE-A-4316611;DE-A-4316622; DE-A-4316876; EP-A-0589839, EP-A-0591102; EP-A-1291384 or3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one,5,7-di-tert-butyl-3-[4-(2-stearoyloxy-ethoxy)phenyl]benzofuran-2-one,3,3′-bis[5,7-di-tert-butyl-3-[4-(2-hydroxyethoxy]phenyl)benzofuran-2-one],5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one,3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(3,4-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(2,3-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,3-(2-acetyl-5-isooctylphenyl)-5-isooctyl-benzofuran-2-one.

The further additives are judiciously employed in amounts of 0.1-10% byweight, for example 0.2-5% by weight, based on the carrier material.

Another embodiment of this invention is an article comprising acomposition containing a carrier material selected from the groupconsisting of a polymer, a solvent and a wax; and a reversiblethermochromic system.

The article is preferably a household article.

Also preferred is a film, a paper, a fiber or a candle wax. Furtherpreferred is a plastic article.

Of special interest is a reversible thermochromic article which is madeby extrusion or injection molding.

The reversible thermochromic system as described above may be used toindicate temperature changes in appliances or devices. The temperaturechange effects color changes which may be assessed by the human eye orby optical devices resulting in an effect signal.

An application of the reversible thermochromic systems as describedabove is in the market of household appliances. For safety reasons thereis often the need that the heated part of a certain device is evidencedthrough the appearance of a different and clearly distinguishable color.

For instance, in small appliances this is often desirable for hotbeverage cups or their respective lids, kettles and percolators,toasters, indoor grills, slow cookers, food steamers, waffle makers,vacuum packaging systems, fryers, deep fryers, irons and rice cookers,where the high temperature may be indicated by the different color of apart of the item itself or of a label. The part or the label can beinterchangeable, so that they can be changed with a new one availableeither in the original package or at the dealer, when the color changeeffect is no longer visible.

A particularly preferred embodiment of the present invention relates tothe use of the reversible thermochromic system to indicate the hightemperature of hot beverage cups or their respective lids by colorchange.

These reversible thermochromic systems can be used in large applianceslike cook-tops, dryers, ovens, space heaters, steam cleaners,dishwashers and washing machines.

The application of a reversible thermochromic system is not limited tothe incorporation into plastic parts of household appliances, but mayfind application also in many other contexts, for example:

-   -   agricultural covers for light regulation purposes, in order to        positively affect the development and harvesting of crops;    -   inks in general, to be used in printing systems or in        color-changing laminates, optionally as microencapsulated        composition;    -   fibers and fabrics in general (both woven and non-woven), for        apparel having fancy and fashionable features and for apparel        and non-apparel purposes with functional characteristics,        including brand protection;    -   toys, including fabrics for clothes and molded objects to        increase the appeal and the amusement from the article;    -   food and non-food packaging, as temperature indicators (“too        hot”: article has to be refrigerated; or: “just the right        temperature”: article is at its best for consumption);    -   promotional items such as hidden messages in tags, cards or        labels; spoons, straws or stirrers for hot-cold drinks.

Of interest is a reversible thermochromic article made of thecomposition as defined above.

Further embodiments of the present invention relate to

the use of a mixture containing components a) and b) as defined above asreversible thermochromic system; anda process for reversibly thermochromically coloring a carrier materialwhich comprises incorporating therein a thermochromic system as definedabove.

A further embodiment of the present invention relates to a compound ofthe formula (IA) or a tautomer thereof

whereinR₁ is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkylsubstituted by 1, 2 or 3 C₁-C₄alkyl; or C₇-C₁₂phenylalkyl;R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ independently of one another are hydrogen, C₁-C₁₈alkyl,C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkyl substituted by 1, 2 or3 C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; andR is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkylsubstituted by 1, 2 or 3C₁-C₄alkyl; or C₇-C₁₂phenylalkyl.

According to a preferred embodiment

R₁ is C₈-C₁₈alkyl,R₂ is hydrogen or a group —SO₂—R;R₃ and R₄ are hydrogen or methyl; andR is C₈-C₁₈alkyl.

The 1,4-dihydroxy-anthraquinones described herein can be synthesized inanalogy to methods known in the art from known starting materials, seefor example E. Jusa, L. Gruen, Monatshefte fuer Chemie (1934), 64, 267;GB 910,222; DE 951,471; G. Schetty, Helvetica Chimica Acta (1962), 45,1026; A. M. Hammam, I. M. Issa, S. A. Amin, H. Dissoki, Journal ofIndian Chemical Society (1977), 54, 729; M. Kamel, S. A. Amin, Journalfuer Praktische Chemie (1967), 36, 230.

In the following examples, percentages given are weight percentagesunless otherwise stated. Percentages are always given in percentages ofthe formulation, composition and/or combination unless otherwise stated.

Commercially Available Additives Used in the Following Examples:

IRGANOX® 8215 is a mixture of IRGAFOS® 168 (66.6%) and IRGANOX® 1010(33.3%)

EXAMPLE 1 Preparation of the Starting Material7,8-bis(dodecylthio)-1,4-dihydroxy-anthraquinone

10 g (32.35 mmoles) of 7,8-dichloro-1,4-dihydroxy-anthraquinone,dimethyl sulfoxide (500 ml), 16.35 g (80.85 mmoles) of dodecanthiol, and17.85 g (129.4 mmoles) of anhydrous potassium carbonate is mixed andstirred at 110° C. for 18 h. The mixture is poured on water (1 L) andneutralised with 2N hydrochloric acid with stirring. The precipitate isfiltered, washed several times with water, and dried in vacuo. Theresidue is dissolved in toluene, the resulting solution is filteredthrough silica gel, the filtrate evaporated and dried. The residue isextracted with hot methanol (1 L), and decanted. The residue issuspended in hexane/pentane 1:1, stirred for 30 min., and filtered.Recrystallisation from hexane/dichloromethane 10:1 gives 6.15 g (30%) ofCompound (1) in a purity of over 95%.

EXAMPLE 2 Preparation of7,8-bis(dodecylsulfonyl)-1,4-dihydroxy-anthraquinone

5 g (7.8 mmoles) of 7,8-bis(dodecylthio)-1,4-dihydroxy-anthraquinone(Compound (1); product of Example 1) are dissolved in chloroform (70ml). 10.76 g (62.4 mmoles) of 3-chloro-perbenzoic acid are added inportions, and the mixture is stirred at 60° C. for 1.5 h. The mixture isdiluted with methanol (300 ml), stirred for 15 min., and filtered. Theresidue is washed with methanol, and dried, yielding 5.1 g (92%) of redCompound (2), m.p. 166-170° C.

EXAMPLE 3 Preparation of the Starting Material7,8-bis(phenylthio)-2,3-dimethyl-1,4-dihydroxy-anthraquinone

5 g (14.83 mmoles) of6,7-dichloro-2,3-dimethyl-1,4-dihydroxy-anthraquinone (3) are mixed withdimethyl formamide (50 ml), 4.08 g (37.07 mmoles) thiophenol and 8.2 g(59.32 mmoles) anhydrous potassium carbonate. The mixture is stirred at110° C. for 3 h, then poured on water (500 ml) and neutralised withhydrochloric acid. The red precipitate is filtered off and washed withwater, then with methanol, then with pentane, and dried. The residue isdissolved in toluene and filtered through silica gel. The filtrate isevaporated to give 5.02 g (70%) of Compound (4), m.p. 255-256° C.

EXAMPLE 4 Preparation of7,8-bis(phenylsulfonyl)-2,3-dimethyl-1,4-dihydroxy-anthraquinone

5 g (10.32 mmoles) of7,8-bis(phenylthio)-2,3-dimethyl-1,4-dihydroxy-anthraquinone (Compound(4), product of Example 3) are dissolved in chloroform (50 ml), 10.68 g(61.92 mmoles) of 3-chloro-perbenzoic acid are added, and the mixture isstirred at 56° C. for 2 h. The mixture is diluted with methanol (200 ml)and stirred at 25° C. The precipitate is filtered off, washed withmethanol, and dried to give 5.08 g (89%) of Compound (5), m.p. 280-282°C.

EXAMPLE 5 Preparation of the Starting Material7,8-bis(dodecylthio)-2,3-dimethyl-1,4-dihydroxy-anthraquinone

5 g (14.83 mmoles) of6,7-dichloro-2,3-dimethyl-1,4-dihydroxy-anthraquinone (3) are mixed withdimethyl sulfoxide (100 ml), 7.5 g (37.05 mmoles) of dodecanthiol, and8.2 g (59.32 mmoles) of anhydrous potassium carbonate. The mixture isstirred at 100° C. for 18 h, then poured on water (500 ml) andneutralised with hydrochloric acid. The red precipitate is filtered offand dissolved in toluene. The organic phase is washed with water,filtered over silica gel, dried over sodium sulfate, and evaporated. Theresidue is recrystallised from pentane to give 3.62 g (36%) of Compound(6), m.p. 101-103° C.

EXAMPLE 6 Preparation of7,8-bis(dodecylsulfonyl)-2,3-dimethyl-1,4-dihydroxy-anthraquinone

3 g (4.48 mmoles) of7,8-bis(dodecylthio)-2,3-dimethyl-1,4-dihydroxy-anthraquinone (Compound(6), product of Example 5) are dissolved in chloroform (60 ml), and 7.73g (44.8 mmoles) of 3-chloro-perbenzoic acid are added. The mixture isstirred at 60° C. for 30 min., cooled and added to methanol (500 ml).The red precipitate is filtered and washed with methanol, and dried invacuo, to give 2.85 g (87%) of Compound (7), m.p. 124-130° C.

EXAMPLE 7 Preparation of 1,4-dihydroxy-2-(phenylsulfonyl)-anthraquinone

1,4-Dihydroxy-2-(phenylsulfonyl)-anthraquinone (8) is prepared accordingto a known procedure of DT 1644441 (DE Offenlegungsschrift 1644441),example 5; m.p. 258-260° C.

Application Examples Example A: Extrusion of Polypropylene Tapes.

A polypropylene powder Profax PH 350 from Basell is dried in a vacuumoven for eight hours at 60° C. 0.05% IRGANOX® 8215 and 0.5% CHIMASSORB®944 are added to the dried polypropylene powder. The compounds are addedin an amount as indicated in Table 1 to obtain the final formulations.The formulations are mixed in a turbo mixer and extruded in a twin-screwextruder equipped with a flat die. In this way, polypropylene tapes areproduced with a width of 5 mm and a thickness of around 1 mm. Theprocessing temperature is around 220° C.

TABLE 1 Colour Colour Compound Amount at 25° C. at 90° C. Compound (2)0.1% blue red Compound (5) 0.1% red-blue red Compound (7) 0.1% violetred

Example B: Extrusion of Polyethylene (Low Density) Tapes.

A polyethylene powder Riblene FF29 from Polimeri Europe is dried in avacuum oven for eight hours at 60° C. 0.05% IRGANOX® 8215 and 0.5%CHIMASSORB® 944 are added to the dried polypropylene powder. Thecompounds are added in an amount as indicated in Table 2 to obtain thefinal formulations. The formulations are mixed in a turbo mixer andextruded in a twin-screw extruder equipped with a flat die. In this way,polyethylene tapes are produced with a width of 5 mm and a thickness ofaround 1 mm. The processing temperature is around 230° C.

TABLE 2 Colour Colour Compound Amount at 25° C. at 90° C. Compound (2)0.1% red-blue red Compound (5) 0.1% red-blue red Compound (8) 0.1% blueorange-red

Example C: Extrusion of Polyethylene (High Density) Tapes.

A polyethylene powder MG 9641 from Borealis is dried in a vacuum ovenfor eight hours at 60° C. 0.05% IRGANOX® B215 and 0.5% CHIMASSORB® 944are added to the dried polypropylene powder. The compounds are added inan amount as indicated in Table 3 to obtain the final formulations. Theformulations are mixed in a turbo mixer and extruded in a twin-screwextruder equipped with a flat die. In this way, polyethylene tapes areproduced with a width of 5 mm and a thickness of around 1 mm. Theprocessing temperature is around 230° C.

TABLE 3 Colour Colour Compound Amount at 25° C. at 90° C. Compound (2)0.1% red-blue red Compound (5) 0.1% red-blue red Compound (8) 0.1%red-blue orange-red

1. A reversible thermochromic system comprising a) a compound of theformula (IA) or a tautomer thereof, or a compound of the formula (IB) ora tautomer thereof

wherein R₁ is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl,C₃-C₁₂cycloalkyl substituted by 1, 2 or 3 C₁-C₄alkyl; phenyl, phenylsubstituted by 1, 2 or 3 C₁-C₄alkyl; or C₇-C₁₂phenylalkyl; R₂ ishydrogen or a group —SO₂—R; R₃ and R₄ independently of one another arehydrogen, C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkylsubstituted by 1, 2 or 3 C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2or 3 C₁-C₄alkyl; or C₇-C₁₂phenylalkyl; and R is C₁-C₁₈alkyl,C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkyl substituted by 1, 2 or3 C₁-C₄alkyl; phenyl, phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; and b) a compound containing a group of the formula


2. A reversible thermochromic system according to claim 1 wherein R₁ isC₈-C₁₈alkyl, allyl, cyclohexyl, phenyl or benzyl; R₂ is hydrogen or agroup —SO₂—R; R₃ and R₄ independently of one another are hydrogen,C₁-C₁₀alkyl, allyl, cyclohexyl, phenyl or benzyl; and R is C₈-C₁₈alkyl,allyl, cyclohexyl, phenyl or benzyl.
 3. A reversible thermochromicsystem according to claim 1 wherein R₁ is C₈-C₁₈ alkyl or phenyl; R₂ ishydrogen or a group —SO₂—R; R₃ and R₄ independently of one another arehydrogen or C₁-C₄alkyl; and R is C₈-C₁₈alkyl or phenyl.
 4. A reversiblethermochromic system according to claim 1 wherein R₁ is C₁₀-C₁₈ alkyl;R₂ is hydrogen or a group —SO₂—R; R₃ and R₄ independently of one anotherare hydrogen or C₁-C₄alkyl; and R is C₁₀-C₁₈alkyl.
 5. A reversiblethermochromic system according to claim 1 wherein component b) is acompound of the formula (C-1-a), (C-1-b), (C-1-c), (C-1-d) or (C-6-a)

wherein b₁ and b₅ are a number from 2 to
 20. 6. A reversiblethermochromic system according to claim 5 wherein component b) is acompound of the formula (C-1-a) or (C-1-b).
 7. A reversiblethermochromic system according to claim 1 wherein component a) is acompound of the formula

and component b) is a compound of the formula (C-1-a) or (C-1-b)

wherein b₁ is a number from 2 to
 20. 8. A reversible thermochromicsystem according to claim 1 wherein the weight ratio of component a) tocomponent b) is 1:1 to 1:20.
 9. A composition containing a carrierselected from the group consisting of a polymer, a solvent and a wax;and a reversible thermochromic system as defined in claim
 1. 10. Acomposition according to claim 9 wherein the carrier material is acoating or an ink.
 11. A composition according to claim 9, whichadditionally contains a further additive selected from the groupconsisting of antioxidants, UV-absorbers, light stabilizers, metaldeactivators, processing stabilizers, thiosynergists, peroxidescavengers, oxygen scavengers, basic co-stabilizers, nucleating agents,fillers, reinforcing agents, flameproofing agents and additionalcolorants.
 12. An article comprising a composition containing a carriermaterial selected from the group consisting of a polymer, a solvent anda wax; and a reversible thermochromic system as defined in claim
 1. 13.An article according to claim 12, which is a household article.
 14. Anarticle according to claim 12, which is a film, a paper, a fiber or acandle wax.
 15. The use of a mixture containing components a) and b) asdefined in claim 1 as reversible thermochromic system.
 16. A process forreversibly thermochromically coloring a carrier material which comprisesincorporating therein a thermochromic system as defined in claim
 1. 17.A compound of the formula (IA) or a tautomer thereof

wherein R₁ is C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₃-C₁₂cycloalkyl,C₃-C₁₂cycloalkyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; R₂ is hydrogen or a group —SO₂—R; R₃ and R₄independently of one another are hydrogen, C₁-C₁₈alkyl, C₂-C₁₈alkenyl,C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkyl substituted by 1, 2 or 3 C₁-C₄alkyl;phenyl, phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; orC₇-C₁₂phenylalkyl; and R is C₁-C₁₈alkyl, C₂-C₁₈alkenyl,C₃-C₁₂cycloalkyl, C₃-C₁₂cycloalkyl substituted by 1, 2 or 3 C₁-C₄alkyl;or C₇-C₁₂phenylalkyl.
 18. A compound according to claim 1 wherein R₁ isC₈-C₁₈alkyl, R₂ is hydrogen or a group —SO₂—R; R₃ and R₄ are hydrogen ormethyl; and R is C₈-C₁₈alkyl.